<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>CSS选择器</title>
    <style>
      blockquote {
        quotes: "“" "”";
      }

      blockquote::before {
        content: open-quote;
      }

      blockquote::after {
        content: close-quote;
      }
    </style>
  </head>
  <body>
    <h1>CSS选择器</h1>
    <blockquote>This is a blockquote.</blockquote>
  </body>
</html>
